DE102007041228A1 - Moisture-based control system for an internal combustion engine - Google Patents

Abstract

A humidity-based control system for an internal combustion engine includes a calculation module and calibration module. The calculation module detects a humidity of air used in a combustion process of the internal combustion engine. The control module selectively controls a spark timing and an exhaust dilution in the engine based on the humidity.

Description

CROSS-REFERENCE TO RELATED REGISTRATIONS

This application claims the priority of the provisional U.S. Application No. 60 / 842,512 filed on 05 September 2006. The disclosure of the preceding application is incorporated herein by reference.

TERRITORY

The The present disclosure relates to an internal combustion engine, and more particularly a method for controlling spark timing and exhaust dilution improve fuel economy and drivability.

BACKGROUND

Of the Efficiency of an internal combustion engine can be adjusted by an adjustment a spark timing and an exhaust dilution, which is burned by the machine to be controlled. The spark timing can be considered generating a spark at a specific time relative to a position of Pistons are defined in a combustion chamber. A preferred spark timing Occurs when the machine has a maximum output power. The output power is directly proportional to the pressure in one Combustion chamber of the machine. To a maximum pressure in the combustion chamber to receive, ignites the Spark that Air / fuel mixture at a time before the piston at top dead center, giving time to the heated gases, to be complete expand when the piston reaches top dead center.

The Engine system can also dilute the air / fuel mixture to to improve the machine efficiency. An exhaust dilution can improve machine efficiency by reducing pumping losses become. When exhaust fumes during an intake stroke of a combustion event are initiated, needed the machine less air, reducing pump power losses of the machine be reduced. An engine control system may be an exhaust gas recirculation (EGR) system use to return exhaust in the intake manifold to lead. additionally For example, a set of cam phasers may be used to provide a Control valve timing to retain exhaust gases in the combustion chamber.

One optimal spark timing and optimal dilution values The machines typically become experimental with a single set of air conditions determined. However, it may be that, due to geographic location, seasonal changes and / or other circumstances do not always work with the same set of states. If the machine power is not the engine system can have a reduced fuel economy and a lethargic Machine down experienced.

SUMMARY

One moisture-based control system for an internal combustion engine according to the present invention The disclosure includes a calculation module and a calibration module. The calculation module determines a humidity of air, which in a combustion process of the internal combustion engine is used. The calibration module selectively controls the spark timing of the engine on the basis of moisture.

According to others The calibration module selectively controls exhaust gas recirculation in the engine Internal combustion engine based on moisture. If the Moisture increases, that increases Calibration module the spark timing and reduces exhaust gas recirculation. If As the humidity decreases, the calibration module reduces the spark timing and increased the exhaust gas recirculation. The Exhaust gas recirculation is with an exhaust gas recirculation valve and / or a cam phaser controlled.

According to others Characteristics, the calculation module comprises a water vapor pressure module, a partial pressure module and a moisture module. The water vapor pressure module generates a water vapor pressure signal based on an intake air temperature signal and a signal of barometric pressure. The partial pressure module generates Partial pressure signal based on a relative humidity signal and the water vapor pressure signal. The moisture modulus is calculated the humidity based on the partial pressure signal and the Signal barometric pressure.

Further Areas of application of the present disclosure will become apparent from the following provided accurate description clearly. It should be understood be that exact description and specific examples, though she the preferred embodiment of the disclosure, are intended for illustration purposes only and are not intended to limit the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The The present disclosure will become apparent from the detailed description and the enclosed drawings, in which:

1 FIG. 12 is a functional block diagram of an example engine system that utilizes a moisture-based control system according to the present disclosure; FIG.

2 FIG. 12 is a functional block diagram of the moisture-based control system according to the present disclosure; FIG. and

3 FIG. 10 is a flowchart illustrating exemplary steps taken by the humidity-based control system to adjust the spark timing and exhaust dilution in accordance with the present disclosure. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The The following description of the preferred embodiment (s) is merely exemplary in nature and in no way intended, the revelation, its application or To limit uses. In this context, the term refers to module or device an application specific integrated circuit (ASIC), an electronic Circuit, a processor (shared, dedicated, or group) and a memory holding one or more software or firmware programs To run, a circuit logic circuit and / or other suitable components, which provide the described functionality.

According to the present Revelation compensates for a moisture-based control system atmospheric conditions while a machine operation. In particular, the moisture-based determines Control system based on various levels of humidity Sensors and sets the spark timing and the dilution an air / fuel mixture based on the moisture level to.

Now up 1 Referring to FIG. 1, a functional block diagram of a machine system 100 a machine 102 which burns an air / fuel mixture to produce a driving torque. Air is through a throttle 106 in an intake manifold 104 sucked. The throttle 106 regulates an air flow in the intake manifold 104 , Air in the intake manifold 104 is on a cylinder 110 distributed. Although four cylinders are shown, it should be noted that the machine 102 additional or less cylinders 110 may include. For example, machines with 2, 3, 4, 5, 6, 8, 10 and 12 cylinders are considered.

A fuel injector (not shown) injects fuel which is combined with air as it enters the cylinder 110 is sucked. A fuel injection system (not shown) provides a desired air-to-fuel ratio in each cylinder 110 ready. An inlet valve 114 opens and closes selectively to allow the air / fuel mixture into the cylinder 110 enter. The intake valve position is through an intake camshaft 116 regulated. A piston (not shown) compresses the air / fuel mixture in the cylinder 110 , A spark plug 118 initiates combustion of the air / fuel mixture that contains the piston in the cylinder 110 drives. The piston drives a crankshaft (not shown) to produce drive torque. The crankshaft drives camshafts 116 . 120 using a timing chain (not shown) to indicate the timing of intake and exhaust valves 114 . 121 to regulate. Although a single intake camshaft and a single exhaust camshaft are shown, it will be appreciated that dual intake camshafts and dual exhaust camshafts may be used in a V-type cylinder configuration. The same applies to an electro-hydraulic valve actuation or other valve systems.

Exhaust gases in the cylinder 110 are forced out of an outlet (not shown) when the exhaust valve 121 is in an open position. The exhaust valve position is through the exhaust camshaft 120 regulated. The exhaust gases are through an exhaust 124 released to the atmosphere.

The machine 102 may be an intake cam phaser 128 and an exhaust cam phaser 130 include a rotational timing of the intake and exhaust camshafts 116 . 120 regulate. In particular, a phase angle of the intake and exhaust cam phasers 128 . 130 be adjusted late or advanced to the rotation timing of the intake and exhaust camshafts 116 . 120 to control. By controlling the timing of the camshaft 116 . 120 For example, the amount of exhaust gases retained in the cylinder can be regulated.

The machine system 100 can an exhaust gas recirculation valve (EGR valve) 132 include. The EGR valve 132 opens and closes selectively to allow exhaust gases to flow back into the intake manifold 104 to regulate. Introducing exhaust gases into an intake stroke of the combustion event tends to limit the amount of oxygen available for combustion. Limiting the available oxygen for combustion lowers combustion temperatures and reduces engine emissions. If the EGR valve 132 is optimized with the spark timing, the fuel economy and / or performance can be improved.

An intake air temperature sensor 136 speaks to an intake air temperature and generates based on an intake air temperature signal 138 , A sensor for barometric pressure 148 responds to atmospheric pressure and generates a barometric pressure signal based on it 150 , A sensor for relative humidity 154 responds to an amount of water that can hold the air based on the temperature and generates a relative humidity signal based thereon 155 , A moisture-based control system 134 controls an operation of the machine 102 based on the intake air temperature signal 138 , the signal of barometric pressure 150 and the relative humidity signal.

Now up 2 Referring to the moisture-based control system 134 a calculation module 170 and a control module 172 , The calculation module 170 determines a humidity based on the intake air temperature signal 138 , the signal of barometric pressure 150 and the relative humidity signal 155 , The control module 172 determines if the humidity has increased or decreased since a previous cycle and generates a control signal to adjust the spark timing and / or dilution of the air / fuel mixture.

The calculation module 170 can be a water vapor saturation pressure module 174 , a partial pressure module 176 and a humidity module 178 include. The water vapor saturation pressure module 174 determines a water vapor saturation pressure value based on the intake air temperature signal 138 and the signal of barometric pressure 150 , In particular, the water vapor saturation pressure value may be determined using the following formula: it = (1.007 + 3.46 × 10 -6 × p) × (0.6064 (17.502 × D ÷ (240.97 + T))) ) where it is the water vapor saturation pressure value, p is the barometric pressure, and T is the intake air temperature. The water vapor saturation pressure module 174 generates a water vapor pressure signal 175 based on the water vapor saturation pressure value.

The partial pressure module 176 determines a partial pressure of the water vapor value based on the relative humidity signal 155 and the water vapor pressure signal 175 , In particular, the partial pressure of the water vapor value can be determined using the following formula: e = (es × φ ÷ 100) where e is the partial pressure of the water vapor value, φ is the relative humidity and it is the water vapor saturation pressure value. The partial pressure module 176 generates a partial pressure signal 177 based on the partial pressure of the water vapor value.

The moisture module 178 determines the humidity based on the partial pressure signal 177 and the signal of barometric pressure 150 , In particular, the moisture can be determined using the following formula: h = (622 × e ÷ (p - e)) / 10 where h is the humidity, p is the barometric pressure and e is the partial pressure of the water vapor value. The moisture module 178 generates a moisture signal 179 on the basis of moisture. The control module 172 generates the control signal at the spark timing and / or dilution of the air / fuel mixture based on the humidity signal 179 readjust.

Now up 3 Referring to exemplary steps of the moisture-based control system 134 generally with 300 designated. The process begins at step 305 when the machine 102 is turned on. At step 310 determines the calculation module 170 the humidity. At step 320 determines the calibration module 172 whether the humidity is increasing or decreasing. In particular, the calibration module compares the humidity to a previous humidity calculated during the previous cycle. As the moisture increases, it will step in 330 the spark timing is advanced. At step 340 reduces the humidity-based control system 134 the dilution of the air / fuel mixture using the EGR valve 132 and / or the cam phaser 128 . 130 , At step 350 determines the moisture-based control system 134 whether the machine 102 running. When the machine is running, the process returns 310 back. If the machine is not running, the process ends at step 360 ,

When the calibration module 170 determines that the moisture at step 320 decreases, the spark timing at step 370 retarded to allow correct combustion phase behavior. At step 380 increases the humidity-based control system 134 the dilution of the air / fuel mixture using the EGR valve 132 and / or the cam phaser 128 . 130 and keep going 350 , In this way, more exhaust gases are introduced to dilute the air / fuel mixture when there is less moisture in the air.

Experts can now precede the from the description, the broad teachings of the present disclosure may be implemented in a variety of forms. Therefore, while this disclosure has been described in conjunction with specific examples thereof, the true scope of the disclosure should not be so limited since those skilled in the art will appreciate other modifications upon studying the drawings, the specification, and the following claims.

Claims (20)

Moisture-based control system for an internal combustion engine, full: a calculation module that absorbs moisture from air determined in a combustion process of the internal combustion engine is used; and a calibration module that has a spark timing the internal combustion engine on the basis of moisture selectively controls. Moisture-based control system according to claim 1, wherein the calibration module an exhaust gas recirculation in the internal combustion engine based on the moisture selectively controls. Moisture-based control system according to claim 2, wherein the calibration module increases the spark timing, when the humidity rises. Moisture-based control system according to claim 3, wherein the calibration module reduces the exhaust gas recirculation when the Moisture rises. Moisture-based control system according to claim 2, where the calibration module reduces the spark timing, when the moisture decreases. Moisture-based control system according to claim 5, wherein the calibration module increases exhaust gas recirculation as moisture decreases. Moisture-based control system according to claim 2, wherein the exhaust gas recirculation with an exhaust gas recirculation valve is controlled. Moisture-based control system according to claim 2, wherein the exhaust gas recirculation with a cam phaser is controlled. Moisture-based control system according to claim 1, wherein the humidity is based on an intake air temperature signal, a signal of barometric pressure and a relative humidity signal based. Moisture-based control system according to claim 9, wherein the calculation module comprises: a water vapor pressure module, a water vapor pressure signal based on the intake air temperature signal and the barometric pressure signal; a partial pressure module, a partial pressure signal based on the relative humidity signal and the water vapor pressure signal generated; and a moisture module, the moisture based on the partial pressure signal and of the barometric pressure signal. Method for calibrating an internal combustion engine, full: Detecting a moisture from air in a combustion process the internal combustion engine is used; and selective taxation of spark timing the internal combustion engine on the basis of moisture. The method of claim 11, further comprising a selective Controlling an exhaust gas recirculation in the internal combustion engine based on the moisture comprising. The method of claim 12, further increasing the spark timing encompassing as the moisture increases. The method of claim 13, further reducing comprising exhaust gas recirculation, when the humidity increases. The method of claim 12, further reducing of spark timing including when the moisture decreases. The method of claim 15, further increasing the Comprising exhaust gas recirculation, when the moisture decreases. The method of claim 12, wherein the exhaust gas recirculation with controlled by an exhaust gas recirculation valve becomes. The method of claim 12, wherein the exhaust gas recirculation with a cam phaser is controlled. The method of claim 11, wherein the moisture on an intake air pressure, a barometric pressure and a based on relative humidity. The method of claim 19, wherein: a water vapor pressure is based on the intake air temperature; a partial pressure based on the relative humidity and the water vapor pressure; and the humidity is based on the partial pressure and the barometric pressure.